osu: add figure for latency tests

garlic/pp/osu-latency.nix

@@ -0,0 +1,31 @@
+{
+  stdenv
+, jq
+}:
+
+inputResult:
+
+stdenv.mkDerivation {
+  name = "osu-latency.json";
+  preferLocalBuild = true;
+  phases = [ "installPhase" ];
+  buildInputs = [ jq ];
+  installPhase = ''
+    touch $out
+    cd ${inputResult}
+    for exp in *-experiment; do
+      cd ${inputResult}/$exp
+      for unit in *-unit; do
+        cd ${inputResult}/$exp/$unit
+        conf=garlic_config.json
+        for run in $(ls -d [0-9]* | sort -n); do
+          awk '/^[0-9]+ +[0-9\.]+$/{print $1, $2}' $run/stdout.log | (
+            while read -r size latency; do
+              jq -cn "{ exp:\"$exp\", unit:\"$unit\", config:inputs, run:$run, \
+                size:$size, latency:$latency }" $conf >> $out
+            done)
+        done
+      done
+    done
+  '';
+}